Manufacture of stitched and cemented footwear



Aug. 30, 1938.

F. HOLLAND MANUFACTURE OF STITCHED AND CEMENTED FOOTWEAR Filed Sept 26,1935 Jam/anion I BY 7: W .A- 645% Patented Aug. 30, 1938 :mrem

MANUFACTURE .OF

s'rrronnn l AND on- M'ENTED FOOTWEAR Friedrich .HolIanG B'rocht n,

, Mass, assignon ,to

' 'C0mpo Shoe Machinery Corporation, New

Yo rk, NrYifacorporation of Delaware Application September 26, 1935,Serial No. 42,180

4 Claims.

Thisinvention relates to the manufacture of footwear andrmoreparticularly to the lubrication, strengthening and protection ofstitching used in such footwear.

Aprimary object of 'theinvention is to provide animproved method forlubricating shoe stitching which is laterto contact a coating suchaspyroxylin cement or the like.

Further objects of the invention are to provide M, animproved meansforprotecting shoe stitching against soiling during passage of .the workthrough the factory, while assuring a firm bond between the stitchedshoe parts.

,,Another object of the invention is to provide n1 a method of making awelted shoe wherein the l outsole is aflixed to thewelt by means ofcement, ,andwherein the inseam stitching is particularly .adapted toprovide, and permitv a strong and gsatisfactory bondhetween thG'fShOBparts in its wicinity,

, Xetanotherobiede e in entioni t me- I vide a w-elted shoe whereinthewelt is attached 15119 thela te p brme e stitching an th outsolel tahe b v a s o cement 1 and in which a lubricant is provided for theincfifia .S i QhiU W C ha an \a t o r is empatjible w t th ce en use tra t the .qu sol Qfill i ob ects oil-t in en i iwill in pa b ;lori9uaand 1 1 in. par a ea hereinafter- The i ventio eceotd n com i tsev- ,.er eP and the re ati -o on m r of Such WPSa-Wit eep e Q-eec o thot ers,- en t "entitle oss t in i heiee re r t eaend h relation ofelements which ;are exemplified-in t the .iel win detailed di closu tscope Qofithe application of whichwill be indicatedin =:;the,,clai n s.i Fora fuller understanding of the nature and 1 40, jects oi theinvent'on referenceshould be had to the following detarled descriptiontakenzin con- ???Qfl c p t e tcqm enrine Q WW in New 1 v r a l is a planview of a pre-formed and pre- ,welted outsole treated in accordance-withone f orm of the present invention;

'Fig. 2 is a longitudinal sectional View taken along/line 2--2 of Fig.1; and

Fig; 3 is a fragmentary transverse sectional viewItaken acrossvthe'forepart of .a lasted welted sho constructed and treated inaccordance. with the present invention. The principles of this inventionare generally e ee le e hem ee eeter 9 i etw e Wh at e l t ee is, 1 1 239? enteel w adi centcoatings such as pyroxylin or like cement=in,thecourse of manufacture or in thefinished'shoe.

Thus, in Fig. 1, there is shown an outsole "l0 having .a weltllvstitched thereto by'means-pf stitching l2. Such a pre-formed and-prewelted outsole issometimes used, for example, inmaking ,mens sportfootw,ear, and it iSBldEvDtEd tQbG ultimately attached to the lasteduppervvhile leaving, a wide extension edgewhich exposes the stitching I2to view.

For ornamental purposessuch stitching is generally made of white orlightly colored thread which gives a color contrast with the leatherused in the welt. With suchlightly colored threads, considerabledifiiculty is encounteredin presenting them in a clean unsoiledcondition in the ultimately finished shoe.

1 In accordance with the present invention such 7 stitching I2 is notonly kept cleanduring-passage of, the Work through thefactory, but it isulti- .-mate1y presented in atpure white condition if white is the lightcolor-desired,which is-not even shaded by the presenceof waxortherlubricant. To this end, the stitching I2 is formed of-wax .freethread which maybe of-linen, cotton, or other acceptable material.'lhisthread isnot Waxed for lubricating purposes, as isgenerally done inleather sewing operations,-but is, instead, in; a preferred exampla wet,or lubricatedewith 7 liquid pyroxylin cement which, is applied theretoshortly before the stitching operation so, that the thread will-be wet,or, that is to, say,- sufi1cien tly moist to enable the pyroxylincoatingtol-actfas a lubricant, during stitching.

The area in the vicinity of thesepyroxylin-cement coated stitches is nowbrushedover with; a coating ,of vpyroxylin cement, designated, 3', whichacts as a protective covering for-thestitching during passage of thework through the shoe tactory. In viewof the use of thiscoating as aprotection, it is important that the stitchingbe wax- -freetasdescribed, since wax, interferesv with or repels suchcement and. isliable to preventthe 4 forming of aneffective coating.

At this stage the stitched area ofwthe shoe has ,a;protective coatingof. cement which is unitary br 95. a so e tht -lub i ati -seat n ofcement occurring on the .exposedportions; of the tch ng a W h 1 9 i comte -,:Q. time ,whenitjsdesired to free thestithinglZ 4 from its,protective coating, a; suitable solvent is brushed over or otherwise;applied to the coati ng i n th p s v p rti n tth est taes J fitmen e vei ei -a i d z ena l s l coating to evaporate or be rubbed entirelyaway. The solvent also removes the pyroxylin lubricant from the exposedportions of the stitching, leaving them in a natural brilliant white oruncolored condition.

While pyroxylin cement comprises a preferred or highly satisfactorysubstance for use as the thread lubricant and coating material, it iscontemplated that stitches may thus be protected and later exposedtoview through use of other suitable lubricants, so long as they aresoluble, liquid, and compatible with, i. e. non-repellant to, thecoating material. Various coating materials likewise may be employed,which should preferably be soluble, together with the lubricant by meansof some common solvent, although this is not strictly essential. Thecoating material may differ from the lubricant Within these desiredlimits, or the same substance may be used for lubricant and coating asin the preferred example given. Examples of suitable lubricating and/orcoating materials are cellulose esters and ethers such as cellulosenitrates (including the preferred pyroxylin cement), cellulose acetate,the methyl, ethyl, 'etc., ethers and the like. Viscose or plaincellulose in a suitable solvent might also be used for lubricatingand/or coating, as well as glues, especially animal glues. It isbelieved that all of these materials are compatible in the sense thatany one may be used as a thread lubricant and any other as a stitchcontacting coating with good results and without any mutual repulsion.

Suitable solvents for the above mentioned lubricating and coatingmaterials will readily occur to those skilled in the art; acetone ismentioned as one such solvent which is generally useful with the namedcellulose compounds as well as others.

While the invention has thus far been described in connection with apre-welted outsole, it will be clear that it is applicable generally toshoe parts wherever stitching is intended to be protected againstsoiling and also wherever lubricated stitching is intended to contact acement coating.

In Fig. 3, a further and highly useful application of the invention isindicated. Here, a welt shoe is made up by providing an insole I lhaving the usual insole lip or rib l to which an upper l6 and a welt I!are attached by stitching designated H2. This stitching is like thatdescribed in the first form in that it is made of wax-free linen orcotton threads which are lubricated with pyroxylin cement, or othersuitable cement of the kinds described above, just prior to the inseamstitching operation so that the applied cement is still wet enough tolubricate during sewing. When thus lubricated, these threads may, ifdesired, be made thinner than usual, say of five strand linen instead ofseven strand, to permit closer inseam trimming. After the inseam issewed, the cement lubricant is allowed to set, and the inseam isthereafter trimmed. The use of pyroxylin or like cement as a lubricantis doubly advantageous in that it not only is superior to wax because ofits compatibility with the cement later used to join the outsole to thewelt, but it permits an extremely close trim at the inseam because thethread also is strengthened by its cement coating, and forms a strong,tight seam wherein every stitch is firmly anchored in place. It is offurther advantage in cemented welt shoes because it enables the welt andinseam portions to be roughed prior to cementing with reduced fear ofweakening the joint at the inseam. That is, the shoe is next reduced atthe inseam and roughed at the welt and inseam and these operations maybe carried quite close to the stitching H2 since even if a strand or twoor even a whole stitch of the latter is broken, the thread still willnot pull out or run because it is firmly anchored in the shoe by meansof its cement lubricating coating which has by this time set.

After the trimming and before theroughing operation, a suitable fillerI8 is applied, and the required amount of this is much less than usualbecause of the closeness of inseam trim available with the pyroxylinlubricated inseam stitches.

Next, an outsole l 9 is afiixed to the welt l1 and .the inseam portionof the upper by means of a cement coating l l3which is applied betweenthese shoe parts. By virtue of the use of a pyroxylin or like cementlubricant, the bond between the outsole and upper is much stronger thancould be obtained with ordinary wax lubricated thread since, asexplained above, wax is incompatible with and repels a cement. Also, thenumber of operations previously needed with conventional waxed thread isreduced, since heretofore the wax had to be stripped from the exposedinseam stitching whenever it was desired to cement in the vicinity. Thewax, too, would get on the hands of operators and thence to the sole andwelting, where it acted to prevent formation of an effective cementedbond. All such difliculties are overcome by the present invention, andin addition, a stronger, better and more closely trimmed welted shoe isprovided.

The cement coating H3 preferably comprises those among the above recitedexamples of materials which have sufliciently strong cementitiousproperties, pyroxylin or other cellulose derivative cements beingpreferred for this purpose. The associated lubricant may comprise any ofthe herein mentioned examples or their like, all of which are compatiblewith any sole afiixing' cement selected from among those described. Thelubricant preferably should be cementitious when used at the inseam andlike places, to secure the advantages of a firmer sewed bond whereinevery stitch is anchored in the leather.

It will be seen that there has been provided an invention which is wellsuited to fulfil its intended functions. Since certain changes incarrying out the above method, and certain modifications in the articlewhich embody the invention may be made without departing from its scope,it is intended that all matter contained in the above description orshown in the accompanying drawing shall be interpreted-as illustrativebe said to fall therebetween.

Having described my invention, what I claim as new and desire to secureby Letters Patent, is:

invention which, as a matter of language, might I. A method ofprotecting shoe stitching from soiling, which comprises, providing awax-free thread, lubricating said thread with a liquid capable offorming a soluble coating, sewing shoe parts together with said threadWhile the lubricant is still wet, applying a soluble coating overexposed portions of said stitching, using said shoe" 7 parts to make ashoe and, after the shoe is completed, dissolving. said coating and thelubricant in the exposed portions of said stitching.

2. A method of protecting shoe stitching from soiling, whichcomprises,providing a wax-free thread, lubricating said thread with aliquid cement comprising a cellulose derivative, sewing shoe partstogether with said thread while the cement lubricant is still wet, andapplying a coating of such cement over exposed portions of saidstitching.

3. A method of protecting shoe stitching from soiling, which comprises,providing a wax-free thread, lubricating said thread with a liquidcement comprising a cellulose derivative, sewing shoe parts togetherwith said thread while the cement lubricant is still wet, applying acoating of such cement over exposed portions of said stitching, usingsaid shoe parts to make a shoe and, after the shoe is completed,dissolving said coating and the lubricant in the exposed portions ofsaid stitching.

4. A method of protecting shoe stitching from soiling, which comprises,providing a wax-free thread, lubricating said thread with a liquidpyroxylin cement, sewing shoe parts together with said thread while thecement lubricant is still wet, applying a coating of pyroxylin cementover exposed portions of said stitching, using said shoe parts to make ashoe and, after the shoe is completed, dissolving said coating and thelubricant in the exposed portions of said stitching.

' FRIEDRICH HOLLAND.

